diff --git a/server/database.js b/server/database.js
index 7deea83d2..42d642794 100644
--- a/server/database.js
+++ b/server/database.js
@@ -3,6 +3,7 @@ const { R } = require("redbean-node");
 const { setSetting, setting } = require("./util-server");
 const { log, sleep } = require("../src/util");
 const knex = require("knex");
+const path = require("path");
 
 /**
  * Database & App Data Folder
@@ -94,19 +95,19 @@ class Database {
         // Data Directory (must be end with "/")
         Database.dataDir = process.env.DATA_DIR || args["data-dir"] || "./data/";
 
-        Database.path = Database.dataDir + "kuma.db";
+        Database.path = path.join(Database.dataDir, "kuma.db");
         if (! fs.existsSync(Database.dataDir)) {
             fs.mkdirSync(Database.dataDir, { recursive: true });
         }
 
-        Database.uploadDir = Database.dataDir + "upload/";
+        Database.uploadDir = path.join(Database.dataDir, "upload/");
 
         if (! fs.existsSync(Database.uploadDir)) {
             fs.mkdirSync(Database.uploadDir, { recursive: true });
         }
 
         // Create screenshot dir
-        Database.screenshotDir = Database.dataDir + "screenshots/";
+        Database.screenshotDir = path.join(Database.dataDir, "screenshots/");
         if (! fs.existsSync(Database.screenshotDir)) {
             fs.mkdirSync(Database.screenshotDir, { recursive: true });
         }
diff --git a/server/uptime-kuma-server.js b/server/uptime-kuma-server.js
index 6781488e5..7817c9e1c 100644
--- a/server/uptime-kuma-server.js
+++ b/server/uptime-kuma-server.js
@@ -11,6 +11,7 @@ const { CacheableDnsHttpAgent } = require("./cacheable-dns-http-agent");
 const { Settings } = require("./settings");
 const dayjs = require("dayjs");
 const childProcess = require("child_process");
+const path = require("path");
 // DO NOT IMPORT HERE IF THE MODULES USED `UptimeKumaServer.getInstance()`, put at the bottom of this file instead.
 
 /**
@@ -214,7 +215,7 @@ class UptimeKumaServer {
      * @param {boolean} outputToConsole Should the error also be output to console?
      */
     static errorLog(error, outputToConsole = true) {
-        const errorLogStream = fs.createWriteStream(Database.dataDir + "/error.log", {
+        const errorLogStream = fs.createWriteStream(path.join(Database.dataDir, "/error.log"), {
             flags: "a"
         });